Shock-absorber.



C. H. MOGMBS.

SHOCK ABSORBER. APPLICATION FILED APR. 7, 1911.

4Patente@ Mar. 5, 1912.

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.To all 'whom t may concern sfrafrns PATENT ernten.

CHAR-LES H. MCCOMBS, F CLEVELAND, OHIO, LASSIGNOR 0F ONE-HALF TO CHARLESS. 'BRITLOI N, OF BRATENAHL, OHIO.

SHQCK-AIBSORBER.

Specification of Letters Patent.

Application filed April 7, 1911. Serial No. 619,548.

Be it known that I, CHARLES H. MCCOMBs, a citizen of the United States,resident of Cleveland, county' of Cuyahoga, and State of Ohio, haveinvented a new? and useful Improvementin Shock-Absorbers, the followingis afspecication, the principle of theiniicntion'zbeing herein explainedand the best Iin'ocleiir which 'I have contemplated lapplying'thatfprincipld so as to distinguish it fr'ofin other inventions. A

lMy inv' tion has reference broadly to l shock absorbers, and moreparticularly to y description set forth indetail such as are intended toalleviate the vibratorymoveinentof vehicle springs.

One objectv sought is the provision of a device 'of this character inwhich the applicat-ion yof resistance may at 'first be of increasing andthen constant degree following the inception of the springs recovery, aswell as during its initial exure.

Another object is the provision of interdependent and hence'more preciseadjusting means:

A further object is the attainment of a more uniform reliability assuredthrough an avoidance of the ineiciency attributable to rapidly wornelements of construction.

The said invention consists of means which are hereinafter fullydescribed and particularly pointedout in the claims.

The annexed drawings and the following certain means embodying myinvention, the disclosed means, however, constituting but one of variousmechanical forms in which the principle of the invention may be applied.

In said annexed drawings :wFigure l is an elevation of a shock absorberemboc'lying my invention as operatively interposed, by

'way of example, between the frame and end. rl`he end a is movablysecured to the bracket lB attached to `the axle vZ2 of the ivehicle,while the piston rod f similarly l secured to a bracket Cattached to the ve- L of which with the usual type of ring d and fibercovhicle frame c. As thus positioned, the dev1ce itself affords theoperative connection generally adopted to check excessive tendencies onthe part of the frame and axle to moverelatively to each other. f

Interiorly, a friction piston D provided.

ering d2 is slidably mounted upon the rod a2. Fixed to the piston rod a2and positioned on either, though inthe drawing the up- Patented Mar. 5,il'. 12.

per, side of the piston D, is a collar E. The

extremity ,o3 of the rodis shown threaded and slotted to receiveaspanner nut F. A

. pair o`f reactive buffer springs e and f" are interposed between thepistoni) and respectivelythe collar E above and th nut F below. rl`hesesprings are preferably,

though notinecess'arily, of strong'and also equal tension, according tothe, type of vehicle to which the device is to be applied and thecharacter of the road upon which it will'likely travel. In practice, thestiffness or tension ofthe springs would probably be such that a'safemargin over and y above the severity of jolts occasioned during ordinaryusage would just fail of moving the piston. The amount of play on thepart vof the springs during such ordinary usage being actually verysmall, these springsy should compress only a little more than half theamount of play of the ordinary usage, previously ascertained.

It is here'evidenced that the amount of free movement made possible bymy construction eventually adjusts itself automatically; and hence isnot restricted, as in the case of devices at present on the market;whenever the vehicle springs are subjected to unusual load.Specifically, while the upper spring 'e4' will be partially compressedunder unusual load, and so for a time restrictv the amount of freemovement; that is,` the movement prior to the movement of the piston;eventually, or after the first appreciable shock which thus moves thepiston, the -t-wo springs e and f reacting will contrive to practicallyrestore the piston to its arbitrarily chosen normal position midway ofthe collar E and' the nut F, though slightly lower than lits firstposition of rest with respect to-the cylinder. The extent to which therange of free Inovement was in the first instance restricted because ofsuch unusual load is consequently bound, the resistance 'is matically.However, as will now be'apparent, the mere turning ofthe Spanner nut Fmay alter the tension of these reactively disposed springs'e and j", andhence constitute one possible mode of adjustment.

The operation of my shock absorber is as follows: Upon a shock.l beingtransmitted to the springs and having flexed. these by compression, thepiston rod a2 will move into the cylinder against the action 'of theupper spring e. -The downward movement of the-frame coincident with thecompression'of the vehicle springs under only a light shock, willdepress this upper sprlng without, however, being sufficient to overcomethe frictional resistance of the piston. Upon the recovery ofthe vehiclespring with its attendant rebound on the 'part of vthe frame, the pistonrod o-n its return stroke will be pulled upwardly through the piston tocompress, in turn, the lower spring f. This simple reactive buffermovement on the part of the springs e and` f', as occasioned 'by lightshocks, will accordingly have no appreciable damping effect upon thevehicle springs other than to assist in a measure their normalcentering. Consojnantly, the maximum range of the free movement which isalways desirable is made possible, and is not only absolutely assuredautomatically, but accurately controlled through the medium of the modeof adjustment already mentioned.

In the event that the shook incurred is sutciently severe to warrant arestraint of the vibratory movement on the part of the springs andespecially the uncomfortable if not damaging rebound on the part of thevehicle frame, the proportionately greater compression of the vehiclesprings again iirst .depresses in similar degree the upper spring euntil its tension is sufficient to overcome the frictional resistance ofthe piston. This causes the latter to slide down continuously, addingits uniform resistance until the initial vibration is checked. Duringthis first movement on the part of the piston, the nut F will have movedeven further and partially reduced the tension of the spring f.Following the recovery of the vehicle spring and. during the ensuing'tendency on the part of the frame to reagain gradually applied whilecompressing this lower spring f and then uniformly maintained by theconstant friction aforded during the return of the piston. At thispoint, attention is directed to a highly advantageous feature which myinvention assures. Of the alternate spring lexures resulting from.-sudden shock, the one 'most requiring restraint is the first excessiveexpansion following recovery, and throughout this entire tendency to soexcessively expand my consti'uetion 'applies the same gradually'increasing and finally thanl necessary, and `hence constant resistance,as in the case of the first compression flexure.- Consequently, there isno omission of restraint at any time throughout those alternate flexuresproperly requiring restraint, andhence the tooV sudden applicationthereof is positively avoided. It is yf'further noted that although 'theneed of shock absorption exists,

the agency calculated to effect it must be no more rigorous no longercumulative directly the excessive resiliency of the vehicle springs hasbegun to be checked. The frictional resistance offered by the piston inmy construction during its reciproationls substantially constant, andaccord-` lngly presents the merits suggested as oontradistinguished intheory from previous efforts of which I am aware. y The modified form ofpiston construct-io shown in Figs. 4t and 5 represents` another Amode ofadjusting my shock absorber, in

this case by altering the degree of friction y offered by the piston.Such adjustment will necessarily be interdependent with that establishedfor the springs et and f. It consists of a plurality of diametricallydisposed springs da positioned between the fiber cov.- ering d2 and anexpansion sleeve d4. The collar d5 assumes in this modification thesliding engagement with the rod a2, vand while designed to inclose the.extremities of Ithe springs e and da d?,

`right and left hand threads,

f in its end depressions 1s exteriorly screwthreaded with as clearlyappearing in Fig. 4.. Two conical nuts all and s areiiiterposed betweenthe sleeve @Z4 and collar dfgfor the now obvious purpose of `being movedtoward andraway from each other to increase ory diminish the tension ofthe springs (Z3. In this manner, the desired degree ,of frictionalyengagementv may be maintained 'regardless of frictional depreciatlon.

Having Y, fully described` my invention,

Patent is:

.1. shock absorber comprising the combination of a cylinder,

what I claim and desire t9 secure by Letters.

apiston rod, and adjustable means said piston adapted toexpand said Athetension of such springs.

L 3. shock absorber comprising the comblnation of a cyllnder, piston insaid cylinder, a friction ring upon said piston, a pis-- i a hollowpiston,a' piston ring provlded with a frictional cov- 1 ton rod movablethrough said piston, projections upon said rod and positioned onopposite sldes of said piston, and springs interposed between saidpiston and projections'l 'adapted to establish an operativerebinatio'nofa cylinder and piston-rod movi able relatively to. eachother; a piston movable. upon said rod;. an expansible piston- Ilring"provided with a frictional covering; adjusting meansassociated withsaidpieton for effecting suchexpanslon; a plurality of reacting resistancemembers adapted to es- 10 tablish an operative relationship between saidrod and piston; and adjustngmeans for one such-resietance member.

Signed by me, this 6th day of April, 1911.

' CHARLES H. MCCOMBS. At'tested by KARL B. Bm'i'roN,

GURT B. MUELLER. p

' copie or this patent may be obtainedfor ve cents each, by addressingthev fvanmialioner tnt.;A rallenta. u

